open Ocamlbuild_plugin
open Command
(* http://brion.inria.fr/gallium/index.php/Using_ocamlfind_with_ocamlbuild *)

(* these functions are not really officially exported *)
let run_and_read = Ocamlbuild_pack.My_unix.run_and_read
let blank_sep_strings = Ocamlbuild_pack.Lexers.blank_sep_strings
   
(* this lists all supported packages *)
let find_packages () =
    blank_sep_strings &
        Lexing.from_string &
        run_and_read "ocamlfind list | cut -d' ' -f1"
                     
(* this is supposed to list available syntaxes, but I don't know how to do it. *)
let find_syntaxes () = ["camlp4o"; "camlp4r"]
                        
(* ocamlfind command *)
let ocamlfind x = S[A"ocamlfind"; x]

let _ = dispatch begin function
    | Before_options ->
        (* by using Before_options one let command line options have an higher priority *)
        (* on the contrary using After_options will guarantee to have the higher priority *)

        (* override default commands by ocamlfind ones *)
        Options.ocamlc   := ocamlfind & A"ocamlc";
        Options.ocamlopt := ocamlfind & A"ocamlopt";
        Options.ocamldep := ocamlfind & A"ocamldep";
        Options.ocamldoc := ocamlfind & A"ocamldoc"
    | After_rules ->
        (*make_tests (test_files ());*)
        
        (* When one link an OCaml library/binary/package, one should use -linkpkg *)
        flag ["ocaml"; "link"] & A"-linkpkg";
                
        (* For each ocamlfind package one inject the -package option when
           * compiling, computing dependencies, generating documentation and
           * linking. *)
        List.iter begin fun pkg ->
            flag ["ocaml"; "compile";  "pkg_"^pkg] & S[A"-package"; A pkg];
            flag ["ocaml"; "ocamldep"; "pkg_"^pkg] & S[A"-package"; A pkg];
            flag ["ocaml"; "doc";      "pkg_"^pkg] & S[A"-package"; A pkg];
            flag ["ocaml"; "link";     "pkg_"^pkg] & S[A"-package"; A pkg];
        end (find_packages ());
                                                                                                         
        (* Like -package but for extensions syntax. Morover -syntax is useless
        * when linking. *)
        List.iter begin fun syntax ->
            flag ["ocaml"; "compile";  "syntax_"^syntax] & S[A"-syntax"; A syntax];
            flag ["ocaml"; "ocamldep"; "syntax_"^syntax] & S[A"-syntax"; A syntax];
            flag ["ocaml"; "doc";      "syntax_"^syntax] & S[A"-syntax"; A syntax];
        end (find_syntaxes ());
        
        (* The default "thread" tag is not compatible with ocamlfind.
        Indeed, the default rules add the "threads.cma" or "threads.cmxa"
        options when using this tag. When using the "-linkpkg" option with
        ocamlfind, this module will then be added twice on the command line.
        
        To solve this, one approach is to add the "-thread" option when using
        the "threads" package using the previous plugin.
        *)
        flag ["ocaml"; "pkg_threads"; "compile"] (S[A "-thread"]);
        flag ["ocaml"; "pkg_threads"; "link"] (S[A "-thread"])
    | _ -> ()
end
